Graphene foils improve angular and energy resolution in neutral atom detectors while also improving mass discrimination and usable energy ranges. We developed improved grid supports and achieved areas >10 cm2 with good foil coverage and significant improvements in secondary electron yield from ~1 nm metal oxide overcoats. We present Luxel’s characterization of large-area graphene foils for applications as transmission filters and detector components.
The Lynx x-ray mission will push thin film filters to larger apertures and thinner profiles than those of any preceding mission. We present a study of the uniformity of deposition with existing technology and the consequences of oxidation on 10-15 nm thick Al films on LUXFilm® polyimide. From visible and infrared transmission measurements of thin aluminum filters and the results of a photon-driven oxidation study at the Beamline 1 of the Synchrotron Ultraviolet Radiation Facility at the National Institute of Standards and Technology, we conclude that, from a deposition and oxidation standpoint, Al optical blocking layers at this thickness are viable.
The Lynx mission concept, under development ahead of the 2020 Astrophysics Decadal Review, includes the Lynx X-ray Microcalorimeter (LXM) as one of its primary instruments. The LXM uses a microcalorimeter array at the focus of a high-throughput soft x-ray telescope to enable high-resolution nondispersive spectroscopy in the soft x-ray waveband (0.2 to 15 keV) with exquisite angular resolution. Similar to other x-ray microcalorimeters, the LXM uses a set of blocking filters mounted within the dewar that pass the photons of interest (x-rays) while attenuating the out-of-band long-wavelength radiation. Such filters have been successfully used on previous orbital and suborbital instruments; however, the Lynx science objectives, which emphasize observations in the soft x-ray band (<1 keV), pose more challenging requirements on the set of LXM blocking filters. We present an introduction to the design of the LXM optical/IR blocking filters and discuss recent advances in filter capability targeted at LXM. In addition, we briefly describe the external filters and the modulated x-ray sources to be used for onboard detector calibration.
Lynx is an x-ray telescope, one of four large satellite mission concepts currently being studied by NASA to be a flagship mission. One of Lynx’s three instruments is an imaging spectrometer called the Lynx x-ray microcalorimeter (LXM), an x-ray microcalorimeter behind an x-ray optic with an angular resolution of 0.5 arc sec and ∼2 m2 of area at 1 keV. The LXM will provide unparalleled diagnostics of distant extended structures and, in particular, will allow the detailed study of the role of cosmic feedback in the evolution of the Universe. We discuss the baseline design of LXM and some parallel approaches for some of the key technologies. The baseline sensor technology uses transition-edge sensors, but we also consider an alternative approach using metallic magnetic calorimeters. We discuss the requirements for the instrument, the pixel layout, and the baseline readout design, which uses microwave superconducting quantum interference devices and high-electron mobility transistor amplifiers and the cryogenic cooling requirements and strategy for meeting these requirements. For each of these technologies, we discuss the current technology readiness level and our strategy for advancing them to be ready for flight. We also describe the current system design, including the block diagram, and our estimate for the mass, power, and data rate of the instrument.
Lynx is an x-ray telescope that is one of four large satellite mission concepts currently being studied by NASA to be the next flagship mission. One of Lynx’s three instruments is the Lynx X-ray Microcalorimeter (LXM), an imaging spectrometer placed at the focus of an x-ray optic with 0.5 arc-second angular resolution and approximately 2 m2 area at 1 keV. It will be used for a wide variety of observations, and the driving performance requirements are met through different sub-regions of the array. It will provide an energy resolution of better than 3 eV over the energy range of 0.2 to 7 keV, with pixels sizes that vary in scale from 0.5 to 1 arc-seconds in the inner 5 arc-minute field-of-view, and to 5 arc-seconds in the extended 20 arc-minute field-of-view.
The Main Array consists mostly of 1 arc-second pixels in the central 5 arc-minutes with less than 3 eV energy resolution (FWHM) in the energy range of 0.2 to 7 keV. It is enhanced in the inner 1 arc-minute region with 0.5 arc-second pixels that will better sample the point spread function of the X-ray optic. The inner 5 arc-minute region is designed specifically for the observations related to cosmic feedback studies, investigating the interactions of AGN with the local regions surrounding them. The 0.5" pixel size allows detailed studies of winds and jets on a finer angular scale. It is also optimized for spatially resolved measurements of cluster cores.
The outer regions of the array are designed to operate during a completely different set of observations. The Extended Array will be utilized for surveys over large regions of the sky, the 20 arc-minute field-of-view making it practical to make observations of the soft diffuse emission from larger scale-structure such as extended galaxies, the outer regions of galaxy groups and clusters and also cosmic filaments. This array is optimized for high energy resolution up to 2 keV through the use of thin (0.5 um) gold absorbers. The Ultra-High-Res Array is designed specifically to enable the study turbulent line broadening around individual through the study of the highly ionized oxygen lines. It is optimized for energy resolution for the oxygen VII and VIII lines, with better than 0.4 eV energy resolution.
In this paper we present the design of the baseline configuration and the scientific motivation. We discuss the technologies that are being developed for this instrument, in particular the transition-edge sensor (TES) and metallic magnetic calorimeter (MMC) sensor technologies. We place these technologies in the context of the required energy resolution, energy range, pixel size, and count-rate, as well as strategies for the pixel layout and wiring. We will discuss the use of microwave SQUIDs, HEMT amplifiers, and parametric amplifiers for the read-out and the implications for the cryogenic design. We also describe the design of the full instrument, including the strawman cryogenic design, as well as an estimate for the mass, power and data rate.
A novel design of X-ray optical system - concentrator for astrophysical rocket experiment is investigated. The proposed system is
based on four modules with Kirkpatrick-Baez (KB) configuration allowing usage of multi-foil mirrors arranged to parabolic profile.
The KB modules are supplemented by rotationally symmetrical parabolic segments. This X-ray optical system effectively uses
a circular aperture. The KB modules are placed in four quadrants while the segments are set into a Cartesian cross between
the KB modules. Studied optical system is under consideration for the student rocket experiment of University of Colorado that
should verify function of NIST’s energy-dispersive detector based on Transition Edge Sensors (TES microcalorimeters).
We present an overview of the Off-plane Grating Rocket for Extended Source Spectroscopy (OGRESS)
sounding rocket payload based at the University of Iowa. OGRESS is designed to perform moderate resolution (R~10-
40) spectroscopy of diffuse celestial X-ray sources between 0.3 – 1.2 keV. A wire grid focuser constrains light from
diffuse sources into a converging beam that feeds an array of diffraction gratings in the extreme off-plane mount. The
spectrum is focused onto Gaseous Electron Multiplier (GEM) detectors. Scheduled to launch in 2014, OGRESS will
obtain accurate physical diagnostics of the Cygnus Loop supernova remnant and will increase the technical readiness
level of GEMs. OGRESS is the fourth-generation of similar payloads from the partnership between the University of
Iowa and the University of Colorado, with higher throughput, and improved noise characteristics over its predecessors.
In this work, we investigate a novel design of optical system for astrophysics. In addition, a new testing method in the X-ray laboratory was verified. The proposed optical system is composed of modules with Kirkpatrick-Baez configuration allowing usage of multi-foil mirrors arranged to parabolic profile. This system effectively uses a circular aperture, which is divided into petals. Individual petals consist of diagonally oriented KB cells with common focus. The hybrid optical system includes a set of rotationally symmetrical parabolic mirrors to achieve higher reflection efficiency of harder X-rays. New results are presented.
In this work, we investigate a novel design of optical system for astrophysics. In addition, a new
testing method in the X-ray laboratory was verified. The proposed optical system is composed of modules with
Kirkpatrick-Baez configuration allowing usage of multi-foil mirrors arranged along a parabolic profile. This
system effectively uses a circular aperture, which is divided into petals. Individual petals consist of diagonally
oriented KB cells with a common focus. This optical system can be improved by a set of nested rotationally
symmetric X-ray mirrors in order to achieve higher reflection efficiency in harder part of considered spectrum.
We report on preliminary results of full aperture X-ray optical tests at the X-ray test facility at the University
of Colorado (USA) of four test modules of Kirkpatrick-Baez (KB) X-ray optical systems performed in August
2010. Direct experimental comparisons were made between gold-coated optics of two novel substrates: glass
foils and silicon wafers. The preliminary results are promising, with full-width half-maxima of full stacks
being of order of 30 arcsec in 2D full arrangement. These results justify further efforts to improve KB optics
for use in low-cost, high-performance space-borne astronomical imaging instruments for X-ray wavelengths.
We present the CODEX sounding rocket payload, a soft x-ray (0.1-1.0 keV) spectrometer designed to
observe diffuse high-surface brightness astronomical sources. The payload is composed of two modules, each with
a 3.25° x 3.25° field of view defined by a stack of wire grids that block light not coming to a 3.0 m focus and admit
only nearly-collimated light onto an array of 67 diffraction gratings in an off-plane mount. After a 2.0 m throw, the
spectrum is detected by offset large-format gaseous electron multiplier (GEM) detectors. CODEX will target the
Vela supernova remnant later this year to measure the temperature and abundances and to determine the
contributions of various soft x-ray emission mechanisms to the remnant's energy budget; resulting spectra will have
resolution (E/▵E) ranging from 50 to 100 across the band. CODEX is the third-generation of similar payloads from
the University of Colorado, with an increased bandpass, higher throughput, and a more robust mechanical structure
than its predecessors.
CODEX is a sounding rocket payload designed to operate in the soft x-ray (0.1-1.0 kV) regime. The instrument has a
3.25 degree square field of view that uses a one meter long wire grid collimator to create a beam that converges to a line
in the focal plane. Wire grid collimator performance is directly correlated to the geometric accuracy of actual grid
features and their relative locations. Utilizing a strategic combination of manufacturing and assembly techniques, this
design is engineered for precision within the confines of a typical rocket budget. Expected resilience of the collimator
under flight conditions is predicted by mechanical analysis.
We describe the experimental apparatus in use to test an off-plane reflection grating for the
soft x-ray (0.3-1.0 keV) bandpass. The grating is a prototype for the X-ray Grating
Spectrometer on the International X-ray Observatory (IXO). It has holographically-ruled
radial grooves to match the converging beam of a 6.5 m focal length telescope. Laboratory
tests are ongoing, with ray tracing indicating that a resolution (ΔE/E) >3,000 is achievable
across the 0.3-1.0 keV bandpass- the requirement to achieve IXO science goals.
We present results from the Extended X-ray Off-Plane Spectrometer (EXOS) sounding rocket payload. The
payload was launched on November 13, 2009 and successfully obtained a spectrum of the Cygnus Loop Supernova
Remnant. The instrument observed in the ~20 - 110 Angstrom bandpass with high resolution (~50) by utilizing an offplane
reflection grating array. This payload is also the 2nd flight for a relatively new type of detector, the Gaseous
Electron Multiplier (GEM) detector. We discuss the performance of these technologies in flight, as well as an overview
of our plans for the next flight of this design.
The International X-ray Observatory (IXO) is a collaborative effort between NASA, ESA, and JAXA. The IXO science
goals are heavily based on obtaining high quality X-ray spectra. In order to achieve this goal the science payload will
incorporate an array of gratings for high resolution, high throughput spectroscopy at the lowest X-ray energies, 0.3 - 1.0
keV. The spectrometer will address a number of important astrophysical goals such as studying the dynamics of clusters
of galaxies, determining how elements are created in the explosions of massive stars, and revealing most of the "normal"
matter in the universe which is currently thought to be hidden in hot filaments of gas stretching between galaxies. We
present here a mature design concept for an Off-Plane X-ray Grating Spectrometer (OP-XGS). This XGS concept has
seen recent significant advancements in optical and mechanical design. We present here an analysis of how the baseline
OP-XGS design fulfills the IXO science requirements for the XGS and the optical and mechanical details of this design.